Preparation of alkynyl-alkenylcarbinols

摘要

Alkynyl-alkenylcarbinols are prepared by reacting a haloepoxyalkane of the formula where X is Cl or Br, and R, R1 are H, CH3 or C2H5, in liquid ammonia with an alkali metal derivative of an alkynyl hydrocarbon of the formula Y-C­CM, where Y is H or an alkyl or aryl group, and M is an alkali metal. Preferably, reaction is effected at the boiling point of the ammonia using a molar excess of the alkali metal derivative. An atmosphere of inert gas such as nitrogen may be used. Reaction times are suitably 5-18 hours. Suitable alkynyl hydrocarbons are acetylene, phenylacetylene, and 1-hexyne, and suitable haloepoxyalkanes are epichlor- (or brom-) hydrin, and brom-2,3-epoxybutane. In examples: (1) sodium is dissolved in liquid ammonia in presence of ferric nitrate to form sodamide, the solution being saturated with acetylene to give sodium acetylide, epichlorhydrin then being added while cooling, ammonium chloride added, ammonia evaporated, and pent-2-en-4-yn-1-ol extracted with ether; (2) epibromhydrin is reacted similarly, yielding the same alkynyl carbinol and a compound of unknown structure; (3) 1-brom-2,3-epoxybutane yielded hex-3-en-5-yn-2-ol, and 2-(2,3-epoxy-1-butoxy)-hex-3-en-5-yne; (4) phenylacetylene is used in a similar process to (1), yielding 5-phenylpent-2-en-4-yn-1-ol; (5) 1-hexyne similarly gives non-2-en-4-yn-1-ol. The products may be partially or completely hydrogenated to give, for example, a dienol; treated with mercury sulphate and sulphuric acid to give a furane derivative; with an amine and formaldehyde to effect the Mannich reaction; oxidized to the corresponding carboxylic acid, for example with chromic acid in acetone; subjected to oxidative coupling in presence of cuprous ammonium chloride to give the p di-yne-glycol which may be hydrogenated to the corresponding alkane diol; or condensed with formaldehyde in presence of cuprous hydroxide.